Reinforcing Increase Of Delta T-C In Mgb2 Smart Meta-Superconductors By Adjusting The Concentration Of Inhomogeneous Phases

Incorporating with inhomogeneous phases with high electroluminescence (EL) intensity to prepare smart meta-superconductors (SMSCs) is an effective method for increasing the superconducting transition temperature (T-c) and has been confirmed in both MgB2 and Bi(Pb)SrCaCuO systems. However, the increase of Delta T-c (Delta T-c = T-c - T-cpure) has been quite small because of the low optimal concentrations of inhomogeneous phases. In this work, three kinds of MgB2 raw materials, namely, (MgB2)-Mg-a, (MgB2)-Mg-b, and (MgB2)-Mg-c, were prepared with particle sizes decreasing in order. Inhomogeneous phases, Y2O3:Eu3+ and Y2O3:Eu3+/Ag, were also prepared and doped into MgB2 to study the influence of doping concentration on the Delta T-c of MgB2 with different particle sizes. Results show that reducing the MgB2 particle size increases the optimal doping concentration of inhomogeneous phases, thereby increasing Delta T-c. The optimal doping concentrations for (MgB2)-Mg-a, (MgB2)-Mg-b, and (MgB2)-Mg-c are 0.5%, 0.8%, and 1.2%, respectively. The corresponding Delta T-c values are 0.4, 0.9, and 1.2 K, respectively. This work open a new approach to reinforcing increase of Delta T-c in MgB2 SMSCs.